Table 1.
Summary statistics of water chemistry parameters in the three zones of the Soyang reservoir studied during 1992–2013.
| Water Quality Attributes | Lacustrine Zone (Lz) | Transition Zone (Tz) | Riverine Zone (Rz) | |||
|---|---|---|---|---|---|---|
| Min-Max | Mean ± Stand Dev | Min-Max | Mean ± Stand Dev | Min-Max | Mean ± Stand Dev | |
| pH | 5.4–9.4 | 7.12 ± 0.57 | 5.2–9.5 | 7.23 ± 0.55 | 5–9.2 | 7.37 ± 0.57 |
| WT | 4–28 | 9.54 ± 5.83 | 1–28 | 12.03 ± 6.61 | 0–30 | 13.92 ± 7.75 |
| DO | 1.1–13.6 | 8.86 ± 2.14 | 0.8–89.6 | 9.4 ± 5 | 3.5–17.7 | 9.87 ± 2.06 |
| BOD | 0.3–2.5 | 1.04 ± 0.3 | 0.1–2.7 | 1.19 ± 0.27 | 0.6–2.6 | 1.27 ± 0.32 |
| COD | 1.1–7.6 | 2.16 ± 0.62 | 1.3–12.8 | 2.27 ± 0.61 | 1.1–5.3 | 2.33 ± 0.56 |
| TN | 0.73–2.9 | 1.50 ± 0.29 | 0.71–4.18 | 1.74 ± 0.44 | 1.01–3.65 | 1.81 ± 0.47 |
| NH4-N | 0–0.34 | 0.02 ± 0.03 | 0–2.05 | 0.03 ± 0.07 | 0–0.14 | 0.03 ± 0.02 |
| TDN | 0.63–2.02 | 1.4 ± 0.23 | 0.77–3.64 | 1.57 ± 0.38 | 0.85–3.42 | 1.58 ± 0.43 |
| NO3-N | 0.09–3.38 | 1.2 ± 0.25 | 0.02–845 | 2.25 ± 27.8 | 0.63–2.7 | 1.36 ± 0.35 |
| TP | 1–237 | 16.5 ± 23.1 | 2–386 | 19.8 ± 23.2 | 2–156 | 20.7 ± 16.7 |
| TDP | 0–1.73 | 0.02 ± 0.15 | 0–1.89 | 0.02 ± 0.16 | 0–0.04 | 0.01 ± 0.01 |
| PO4-P | 0–0.06 | 0 ± 0.01 | 0–0.11 | 0 ± 0.01 | 0–0.03 | 0 ± 0 |
| TN:TP | 6.35–1239 | 158.4 ± 110.3 | 5.72–663 | 129.4 ± 80.6 | 15.9–558 | 120.4 ± 74.6 |
| SD | 3.4–100 | 43.8 ± 32.5 | 0.2–60 | 17.4 ± 15.3 | 0.2–45 | 6 ± 5.69 |
| TSS | 0–168 | 4.58 ± 13.7 | 0.1–216 | 6.16 ± 16.2 | 0.2–179 | 7.38 ± 18.9 |
| EC | 41–432 | 68.37 ± 23.84 | 10–127 | 70.16 ± 14.75 | 0–128 | 70.88 ± 16.25 |
| TCB | 0–350 | 48.13 ± 59.01 | 0–1600 | 112.5 ± 211.1 | 2–2400 | 170.6 ± 305.6 |
| Chl-a | 0–24.8 | 2.9 ± 3.29 | 0–40.1 | 4.61 ± 4.98 | 0–85.8 | 4.55 ± 7.52 |
Note: Min = Minimum; Max = Maximum; Stand Dev = Standard deviation; SD = Secchi disk (m); DO = Dissolved oxygen (mg/L); BOD = Biological oxygen demand (mg/L); COD = Chemical oxygen demand (mg/L); TSS = Total suspended solids (mg/L); TN = Total nitrogen (mg/L); NH4-N = Ammonia nitrogen (mg/L); NO3-N = Nitrate nitrogen (mg/L); TP = Total phosphorus (µg/L); TN:TP = Ambient ratios of TN and TP; WT = Water temperature (°C); EC = Electrical conductivity (mS/cm); TCB = Total coliform bacteria, TDN = Total dissolved nitrogen (mg/L); TDP = Total dissolved phosphorus (mg/L); PO4-P = Phosphate phosphorus (mg/L); Chl-a = Chlorophyll-a (µg/L).